ES2725323T3 - An oxidation process to produce a crude and / or purified carboxylic acid product - Google Patents

Abstract

A process for producing a composition (710) of dry purified carboxylic acid comprising furan-2,5-dicarboxylic acid (FDCA), said process comprising step (a): step (a) comprises oxidizing in a zone (125) of primary oxidation at least one oxidizable compound in a stream (30) of oxidizable raw material comprising 5-HMF in the presence of a stream (10) of oxidizing gas, a stream of solvent (20) comprising a solvent of saturated organic acid having 2 to 6 carbon atoms with the presence of water and a catalytic system at a temperature of 100 ° C to 220 ° C to produce a composition (110) of crude carboxylic acid comprising FDCA; wherein said primary oxidation zone (125) comprises at least one oxidation reactor and wherein said catalytic system comprises cobalt in a range of 500 ppm by weight to 6000 ppm by weight with respect to the weight of the liquid in the reaction medium, manganese in an amount ranging from 2 ppm by weight to 600 ppm by weight with respect to the weight of the liquid in the reaction medium and bromine in an amount ranging from 300 ppm by weight to 4500 ppm by weight with respect to the weight of the liquid in the reaction medium, where the ratio of cobalt to manganese by weight is at least 10: 1.

Description

DESCRIPTION

An oxidation process to produce a crude and / or purified carboxylic acid product

Field of the Invention

The present invention relates to a process for producing a carboxylic acid composition as defined in claim 1. The process comprises the oxidation of 5- (hydroxylmethyl) furfural in the presence of oxygen, a saturated organic acid solvent having 2 at 6 carbon atoms with the presence of water, and a catalytic system comprising cobalt, manganese and bromine at a temperature of 100 ° C to 220 ° C to produce the carboxylic acid composition comprising furan-2,5-dicarboxylic acid .

Background of the invention

Aromatic dicarboxylic acids, such as terephthalic acid and isophthalic acid, are used to produce a variety of polyester products. Important examples of which are poly (ethylene terephthalate) and its copolymers. These aromatic dicarboxylic acids are synthesized by catalytic oxidation of the corresponding aromatic dialkyl compounds that are obtained from fossil fuels, which are described in US Pat. 2006/0205977 A1, which is incorporated herein by reference to the extent that it does not contradict the statements in this document.

There is a growing interest in the use of renewable resources as a raw material for the chemical industry, mainly due to the progressive reduction of fossil reserves and their related environmental impacts. Furan-2,5-dicarboxylic acid (FDCA) is a versatile intermediate considered as the promising alternative with a biological base closest to terephthalic acid and isophthalic acid. Like aromatic diacids, the FDCA can be condensed with diols such as ethylene glycol to obtain polyester resins similar to polyethylene terephthalate (PET) (Gandini, A .; Silvestre, A. J; Neto, CP; Sousa, AF; Gomes, MJ Poly. Sci. A 2009, 47, 295.). Therefore, there is a need in the chemical industry for an efficient process for producing carboxylic acid compositions, especially FDCA. This document provides a high performance procedure (minimum 90% FDCA yield) to produce a dry purified FDCA product.

Brief description of the drawings

Figure 1 illustrates different embodiments of the invention wherein a process for producing a dry purified 710 carboxylic acid is provided.

Figure 2 illustrates an embodiment of the invention, showing the GC chromatogram of the carboxylic acid composition 110 that has been dried.

Figure 3 illustrates an embodiment of the invention, showing a 1 H NMR of the carboxylic acid composition 110 that has been dried.

Figure 4 illustrates an embodiment of the invention, showing a 13 C {1 H} NMR of the carboxylic acid composition 110 that has been dried.

Figure 5 illustrates an embodiment of the invention, showing the effects of temperature, pressure, cobalt and bromine concentrations on FDCA yield in carboxylic acid composition 110.

Figure 6 illustrates an embodiment that does not belong to the invention, effect of temperature on performance using a stream 30 of oxidizable raw material comprising 5-AMF. The symbol represents that Co is 2000 ppm and Br is 3000 ppm. The symbol x represents that Co is 2500 ppm and Br is 2500 ppm.

Figure 7 illustrates an embodiment that does not belong to the invention, effect of temperature on performance using a stream 30 of oxidizable raw material comprising 5-EMF. The symbol represents that Co is 2000 ppm and Br is 3000 ppm. The symbol x represents that Co is 2500 ppm and Br is 2500 ppm.

Detailed description

It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions can be provided in the description above, such as when accompanying the use of a term defined in context.

As used in this document, the terms "a / a", and "the" mean one or more.

As used herein, the term "and / or", when used in a list of two or more articles, means that any of the items listed may be used alone or any combination of two or more of The items listed. For example, if a composition containing components A, B and / or C is described, the composition may contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

As used herein, the terms "comprising", "comprises" and "comprise" are open transition terms that are used to transition from a subject recited before the term to one or more elements recited after the term , where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

As used herein, the terms "having", "has" and "have" have the same open meaning as "comprising", "comprising" and "comprising" provided above.

As used herein, the terms "including", "including", and "include" have the same open meaning as "comprising", "comprises" and "comprise" provided above.

The present description uses numerical ranges to quantify certain parameters related to the invention. It should be understood that when numerical intervals are provided, it should be interpreted that said intervals provide literal support for the limitations of the claims that only recite the lower value of the interval, as well as the limitations of the claims that only recite the upper value of the interval. For example, a described numerical range of 10 to 100 provides literal support for a claim that recites "greater than 10" (without upper limits) and a claim that recites "less than 100" (without lower limits).

The present description uses specific numerical values to quantify certain parameters related to the invention, where specific numerical values are not expressly part of a numerical range. It should be understood that each specific numerical value provided in this document should be interpreted as a literal support for a wide, intermediate and limited range. The wide range associated with each specific numerical value is the numerical value plus and minus 60 percent of the numerical value, rounded to two significant digits. The intermediate range associated with each specific numerical value is the numerical value plus and minus 30 percent of the numerical value, rounded to two significant digits. The limited range associated with each specific numerical value is the numerical value plus and minus 15 percent of the numerical value, rounded to two significant digits. For example, if the specification describes a specific temperature of 17 ° C (62 ° F), that description provides literal support for a wide numerical range of -4 ° C to 37 ° C (16.5 ° C / - 20.5 ° C) [ 25 ° F to 99 ° F (62 ° F / - 37 ° F)], an intermediate numerical range of 6 ° C to 27 ° C (16.5 ° C / 10.5 ° C) [43 ° F to 81 ° F ( 62 ° F / - 19 ° F)], and a limited numerical range of 11 ° C to 22 ° C (16.5 ° C / - 5.5 ° C) [53 ° F to 71 ° F (62 ° F / - 9 ° F)]. These broad, intermediate and limited numerical intervals should apply not only to specific values, but also apply to differences between these specific values. Therefore, if the specification describes a first pressure of 7.7 bar (110 psia) and a second pressure of 3.4 bar (48 psia) (a difference of 4.3 bar (62 psi)), the wide, intermediate and limited intervals for the The pressure difference between these two streams would be 17.5 bar at 6.9 bar (25 to 99 psi), 3.0 bar at 5.7 bar (43 to 81 psi) and 3.7 bar at 5 bar (53 to 71 psi), respectively.

The invention provides a process for producing a dry purified 710 carboxylic acid composition comprising furan-2,5-dicarboxylic acid (FDCA) as defined in claim 1. The embodiments of the process are depicted in Figure 1. The process comprises oxidation of at least one oxidizable compound in a stream 30 of oxidizable raw material in the presence of a stream 10 of oxidizing gas, stream 20 of solvent, and at least one catalytic system. Stream 30 of oxidizable raw material comprises at least one oxidizable compound suitable for producing a carboxylic acid composition 110 comprising FDCA. The amount of FDCA in the carboxylic acid composition 110 may vary from more than 10 percent by weight in the carboxylic acid composition 110, more than 20 percent by weight in the carboxylic acid composition 110, more than 30 percent by weight. weight in the composition 110 of carboxylic acid. Composition 110 of the carboxylic acid comprises FDCA and solvent.

Stream 30 of oxidizable raw material comprises 5- (hydroxymethyl) furfural (5-HMF), to generate a carboxylic acid composition comprising FDCA. The process may optionally include removing impurities from the carboxylic acid composition 110 in a liquid displacement zone 225 to form a low impurity suspension stream 210. The low impurity suspension stream 210 can be further treated in a secondary oxidation zone 335 to produce a secondary oxidation suspension stream 310 that can be routed to a crystallization zone 425 to form a crystallized suspension stream 410. The crystallized suspension stream 410 is cooled in a cooling zone 430 and the crystallized cooled suspension stream 510 can be directed to a solid-liquid separation zone 625 to generate a stream 6 of purified wet cake comprising FDCA which is dried in a drying zone 725 to generate a dry purified carboxylic acid 710 comprising purified FDCA.

According to the invention, there is provided a process for producing a dry purified 710 carboxylic acid comprising dry purified furan-2,5-dicarboxylic acid (FDCA) and comprises the following step (a):

Step (a) comprises oxidizing at least one oxidizable compound in a stream 30 of oxidizable raw material in the presence of a stream 10 of oxidizing gas, stream 20 of solvent, and at least one catalytic system in a primary oxidation zone 125 comprising at least one primary oxidizing reactor to produce a carboxylic acid composition 110 comprising furan-2,5-dicarboxylic acid (FDCA); wherein stream 30 of oxidizable raw material comprises 5- (hydroxymethyl) furfural (5-HMF). The structures for the various compounds of oxidizable raw materials are summarized below:

5-HMF or its derivatives are oxidized with elemental O ² in multi-stage reactions, equations 1 and 2, to form FDCA with 5-formyl furan-2-carboxylic acid (FFCA) as a key intermediate.

In one embodiment of this invention, the streams directed to the primary oxidation zone 125 comprise a stream 10 of oxidizing gas comprising oxygen and a stream 20 of solvent comprising solvent, a stream 30 of oxidizable raw material, and a catalytic system. Stream 30 of oxidizable raw material comprises a continuous liquid phase. In another embodiment of the invention, stream 30 of oxidizable raw material, stream 10 of oxidizing gas, stream 20 of solvent and the catalytic system can be fed to zone 125 of primary oxidation as separate and individual streams or combined in any combination before entering the primary oxidation zone 125 where said feed streams can enter a single location or multiple locations in the primary oxidation zone 125.

Composition 110 of the carboxylic acid comprises FDCA. In one embodiment of the invention, the carboxylic acid composition 110 comprises FDCA and FFCA and at least one of 2,5-diformylfuran in an amount ranging from 0% by weight to about 0.2% by weight, levulinic acid in an amount that it ranges from 0% by weight to 0.5% by weight, succinic acid in an amount ranging from 0% by weight to 0.5% by weight and acetoxy acetic acid in an amount ranging from 0% by weight to 0.5% by weight.

In another embodiment of the invention, the carboxylic acid composition 110 comprises FDCA, FFCA and EFCA. In another embodiment of the invention, the EFCA in the carboxylic acid composition 110 in a range of about 0.05% by weight to 4% by weight, or about 1% by weight to 2% by weight.

The catalyst system comprises at least one catalyst suitable for oxidation comprising cobalt, bromine and manganese compounds, which are soluble in the selected oxidation solvent. In another embodiment of the invention, the catalyst system comprises cobalt, manganese and bromine wherein the weight ratio of cobalt to manganese in the reaction mixture is 10 to 400 and the weight ratio of cobalt to bromine is 0.7 to 3.5 .

The oxidizing gas stream comprises oxygen. Examples include, but are not limited to, air and purified oxygen. The amount of oxygen in the primary oxidation zone varies from about 5 mol% to 45 mol%, 5 mol% to 60 mol%, 5 mol% to 80 mol%.

According to the invention, the solvents comprise aqueous solutions of C ² to Ce monocarboxylic acids, for example, acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, trimethylacetic acid, caprioic acid and mixtures thereof. same.

The most common solvent used for oxidation is an aqueous solution of acetic acid, which typically has a concentration of 80 to 99% by weight. In especially preferred embodiments, the solvent comprises a mixture of water and acetic acid having a water content of up to 15% by weight. In addition, a portion of the solvent feed to the primary oxidation reactor can be obtained from a recycle stream obtained by displacing approximately 80 to 90% of the mother liquors taken from the crude reaction mixture stream discharged from the primary oxidation reactor. with new and moist acetic acid, which contains up to 15% water.

Solvents include mixtures of aliphatic monocarboxylic acids containing 2 to 6 carbon atoms with water. Examples of aliphatic monocarboxylic acids include, but are not limited to, acetic acid.

The oxidation temperature varies from 100 ° C to 220 ° C and from 110 ° C to 160 ° C.

The process is provided to produce furan-2,5-dicarboxylic acid (FDCA) with high yields by oxidation in liquid phase that minimizes solvent and loss of starting material through carbon burning. The process comprises the oxidation of at least one oxidizable compound in a stream 30 of oxidizable raw material in the presence of a stream 10 of oxidizing gas, stream 20 of solvent, and at least one catalyst system in a zone 125 of primary oxidation; wherein the oxidizable compound is 5- (hydroxymethyl) furfural (5-HMF). The oxidizable compound can be oxidized in a solvent comprising acetic acid with the presence of water with oxygen in the presence of a catalytic system comprising cobalt, manganese and bromine, wherein the weight ratio of cobalt to manganese in the reaction mixture is from 10 to 400 and the weight ratio of cobalt to bromine is 0.7 to 3.5. Such a catalytic system with an improved Co: Mn ratio can lead to high FDCA performance. In this procedure, the oxidation temperature ranges from 100 ° C to 220 ° C, or another range of about 110 ° C to about 160 ° C, which can minimize carbon burning. The cobalt concentration of the catalyst can vary from 1000 ppm to 6000 ppm, and the amount of manganese from 2 ppm to 600 ppm, and the amount of bromine from 300 ppm to 4500 ppm with respect to the total weight of the liquid in the reaction medium. from zone 125 of primary oxidation. As used herein, the process temperature is the temperature of the reaction mixture within the primary oxidation zone where the liquid is present as the continuous phase. The primary oxidation reactor will typically be characterized by a lower section where gas bubbles are dispersed in a continuous liquid phase. Solids may also be present in the lower section. In the upper section of the primary oxidant, the gas is in the continuous phase and droplets of liquid may also be present.

The catalytic compositions employed in the processes of the invention comprise cobalt atoms, manganese atoms and bromine atoms, supplied by any suitable means, as described below. The catalytic composition is typically soluble in the solvent under reaction conditions, or is soluble in the reagents fed to the oxidation zone. Preferably, the catalyst composition is soluble in the solvent at 40 ° C and 0.96 bar (1 atm), and is soluble in the solvent under the reaction conditions.

Cobalt atoms can be provided in ionic form as inorganic cobalt salts, such as cobalt bromide, cobalt nitrate or cobalt chloride, or organic cobalt compounds such as cobalt salts of aliphatic or aromatic acids having 2-22 carbon atoms, including cobalt acetate, cobalt octanoate, cobalt benzoate, cobalt acetylacetonate and cobalt naphthalate. The oxidation state of cobalt when added as a compound to the reaction mixture is not limited, and includes oxidation states 2 and 3.

Manganese atoms can be provided as one or more inorganic manganese salts, such as manganese borates, manganese halides, manganese nitrates or organometallic manganese compounds such as manganese salts of lower aliphatic carboxylic acids, including acetate manganese, and manganese salts of beta diketonates, including manganese acetylacetonate.

The bromine component can be added as elemental bromine, in combination, or as an anion. Suitable sources of bromine include hydrobromic acid, sodium bromide, ammonium bromide, potassium bromide and tetrabromoethane. Hydrobromic acid or sodium bromide may be preferred sources of bromine.

In another embodiment of the invention, there is provided a process for producing furan-2,5-dicarboxylic acid (FDCA) in high yields by liquid phase oxidation that minimizes the loss of solvent and starting material through carbon burning. The process comprises the oxidation of at least one oxidizable compound in a stream 30 of oxidizable raw material in the presence of a stream 10 of oxidizing gas, stream 20 of solvent, and at least one catalyst system in a zone 125 of primary oxidation; wherein said oxidizable compound is 5- (hydroxymethyl) furfural (5-HMF); wherein said solvent stream comprises acetic acid with the presence of water; wherein said catalytic system comprises cobalt, manganese and bromine, wherein the weight ratio of cobalt to manganese in the reaction mixture is from 10 to 400. In this process, the temperature varies from 100 ° C to 220 ° C, of 105 ° C to 180 ° C, and from 110 ° C to 160 ° C. The cobalt concentration of the catalytic system can vary from about 1000 ppm to about 6000 ppm, and the amount of manganese can vary from about 2 ppm to about 600 ppm, and the amount of bromine can vary from about 300 ppm to about 4500 ppm with with respect to the total weight of the liquid in the reaction medium.

According to the invention, the process comprises oxidizing at least one oxidizable compound in a stream 30 of oxidizable raw material in the presence of a stream 10 of oxidizing gas, stream 20 of solvent, and at least one catalyst system in an oxidation zone 125 primary; wherein said oxidizable compound is 5- (hydroxymethyl) furfural (5-HMF); wherein said solvent stream comprises a saturated organic acid having from 2 to 6 carbon atoms with the presence of water at a temperature of 100 ° C to 220 ° C to produce a dicarboxylic acid composition; wherein the primary oxidation zone 125 comprises at least one primary oxidation reactor and wherein the catalyst system comprises cobalt in a range of 500 ppm by weight to 6000 ppm by weight with respect to the weight of the liquid in the reaction medium, manganese in an amount ranging from 2 ppm by weight to 600 ppm by weight with respect to the weight of the liquid in the reaction medium and bromine in an amount ranging from 300 ppm by weight to 4500 ppm by weight with respect to the weight of the liquid in The reaction medium.

According to the present invention, wherein the stream 30 of oxidizable raw material comprises 5-HMF, the weight ratio of cobalt to manganese is at least 10: 1. Other possible reasons are at least 15: 1, 20: 1, 25: 1, 30: 1, 40: 1, 50: 1, 60: 1, or 400 to 1.

In another embodiment of the invention, when the stream 30 of oxidizable material comprises mixed raw materials of 5-HMF and 5-HMF, and mixed raw materials of 5-HMF and 5-alkylfurfurals, the ratio of cobalt to manganese by weight of the system Catalytic is at least 10: 1, 20: 1, 50: 1, 100: 1 or 400: 1.

In an embodiment that does not belong to the invention, furan-2,5-dicarboxylic acid (FDCA) can be obtained by liquid phase oxidation of 5- (hydroxymethyl) furfural (5-HMF), 5- (acetoxymethyl) furfural (5- AMF)) and 5- (ethoxymethyl) furfural (5-EMF) with molecular oxygen using a Co / Mn / Br catalyst system in an acetic acid solvent. After oxidation of 5-HMF / 5-AMF / 5-EMF in the presence of acetic acid, the FDCA precipitates from the solution. After filtration, washing with acetic acid and then with water and drying, solids were obtained with a minimum of 90%, 92%, 94%, 96% Fd Ca content by weight.

In another embodiment that does not belong to the invention, the FDCA is obtained by liquid phase oxidation of 5-HMF, 5-AMF and 5-EMF with molecular oxygen using a Co / Mn / Br catalyst system in an acetic acid solvent. After oxidation of 5-HMF / 5-AMF / 5-EMF in acetic acid, the FDCA precipitates from the solution. After filtration, washing with acetic acid and then with water, and drying, solids with a minimum FDCA content of 96% and a maximum of b * of 15, 16, 17, 18, 19 or 20 were obtained.

b * is one of the attributes of three colors measured in an instrument based on spectroscopic reflectance. Color can be measured with any device known in the art. A Hunter Ultrascan XE instrument is typically the measuring device. Positive readings mean the degree of yellow (or absorbance of blue), while negative readings mean the degree of blue (or absorbance of yellow).

In another embodiment of the invention, there is provided a process for producing furan-2,5-dicarboxylic acid (FDCA) with minimum yields of 80% or 85% or 90% or higher by liquid phase oxidation that minimizes solvent loss and Starting material through carbon burning. As used herein, the yield is defined as the mass of FDCA obtained divided by the theoretical amount of FDCA that must be produced based on the amount of raw material used. For example, if one mole or 126.11 grams of 5-HMF is oxidized, it would theoretically generate one mole or 156.01 grams of FDCA. If, for example, the actual amount of FDCA formed is only 150 grams, the yield of this reaction is calculated to be = (150 / 156.01) times 100, which is equivalent to a yield of 96%. The same calculation applies to the oxidation reaction performed using 5-HMF derivatives or mixed feeds.

In another embodiment of this invention, there is provided a process comprising oxidizing at least one oxidizable compound in a stream 30 of oxidizable raw material in the presence of a stream 10 of oxidizing gas, stream 20 of solvent, and at least one catalyst system in a primary oxidation zone 125; where said compound oxidizable is selected from 5- (hydroxymethyl) furfural (5-HMF); wherein said solvent stream comprises acetic acid with the presence of water; wherein said catalyst system comprises cobalt, manganese and bromine, wherein the weight ratio of cobalt to manganese in the reaction mixture is from about 10 to about 400 and the weight ratio of cobalt to bromine is about 0.7 to about 3.5 . Such a catalytic system with an improved Co: Mn and Co: Br ratio can lead to high FDCA yield (minimum of 90%), a decrease in impurity formation (measured by b *) that causes color in the descending polymerization process while maintaining the amount of CO and CO ² in the waste gas at least.

The temperature in the primary oxidation zone varies from 100 ° C to 220 ° C, and can vary from 110 ° C to 160 ° C or can vary from 105 ° C to 180 ° C or from 100 ° C to 200 ° C, or 100 ° C. ° C to 190 ° C. An advantage of the primary oxidation conditions described is the low carbon burning, as illustrated in Table 1. The oxidant gas stream 120 is sent to the residual oxidant gas treatment zone 825 to generate a stream 810 of inert gas , liquid stream 820 comprising water and a stream 830 of recovered solvent comprising condensed solvent. In one embodiment, at least a portion of the recovered solvent stream 830 is directed to wash the fed stream 620 and the combined stream is directed to the solid-liquid separation zone 625 in order to wash the solids present in the 625 zone solid-liquid separation. In one embodiment, the inert gas stream 810 can be vented to the atmosphere. In another embodiment, at least a portion of the inert gas stream 810 can be used as an inert gas in the process to inert containers and / or to transport gas for solids in the process.

In another embodiment of the invention, the composition of the liquid phase within the primary oxidant may have a pH of about -4.0 to about 1.0 or the pH of the raw material is about -1.8 to about 1.0, or the pH of the matter Premium is about -1.5 to about 1.0.

It should be understood that steps (b) - (g) are optional and only one possible embodiment of a process for purifying the carboxylic acid composition.

Step (b) comprises directing the crude carboxylic composition 110 and the stream of solvent of new contribution to a liquid displacement zone 225 to produce a displaced mother liquor stream 230 and a low impurity suspension stream 210 comprising FDCA . The displaced mother liquor stream 230 comprises solvent and soluble matter dissolved in the solvent comprising dissolved impurities and dissolved catalyst. In various embodiments of the invention, from 5% to 99%, from 30% to 90%, and most preferably from 50 to 85% of mother liquors present in the carboxylic acid composition 110 is displaced in the displacement zone 225 of the liquid resulting in dissolved matter comprising impurities present in displaced mother liquor that does not progress in the process. Sufficiently fresh solvent is fed to the displacement zone 225 of the liquid that is mixed with the solids present resulting in a low impurity suspension stream 210 being pumpable with a weight% solids ranging from 1% to 50% , 10% to 40%, and preferably the% by weight of solids in stream 210 will vary between 25% and 38%.

The liquid displacement zone may be a single unit operation or multiple unit operations. In one embodiment of the invention, the liquid displacement zone 225 may be any solid-liquid separation device capable of generating an isolated wet cake from a feed suspension and then mixing the isolated wet cake with fresh solvent in a separate mixing device to generate the low impurity suspension current 210. Examples of suitable solid liquid separation devices include, but are not limited to, a continuous pressure drum filter, solid cuvette centrifuges that include, but are not limited to, decanter and disc stacking centrifuges, and pressure filters of lots that include, but are not limited to, candle and leaf filters. The preferred solid-liquid separation device for this application is a continuous pressure drum filter. The solid-liquid separator operates at temperatures between 30 degrees C. and 200 degrees C., preferably from 80 degrees C. to 170 degrees C. The solid-liquid separator in the liquid displacement zone 225 may be operated continuously or discontinuous, although it will be appreciated that for commercial processes, continuous mode is preferred. Alternatively, a portion of the mother liquor in stream 110 is displaced with a stream 220 of fresh solvent in a single device to form low impurity suspension stream 210 without forming an insulated wet cake.

In one embodiment, 5% to 100% by weight of the displaced mother water stream 230 is directed to a purge zone 235 where a portion of the impurities present in stream 230 is isolated and exits the process as stream 920 of purge, where a portion is 5% by weight or greater. The solvent stream 910 recovered comprises solvent and catalyst isolated from stream 230 and is recycled to the process. In one embodiment, the recovered solvent stream 910 is recycled to the primary oxidation zone 125 and contains more than 30% of the catalyst that entered the purge zone 235 in stream 230. In another embodiment, stream 910 is recycled to the primary oxidation zone 125 and contains more than 50% by weight, contains more than 70% by weight and, preferably, more than 90% by weight of the catalyst entering the purge zone 235 in the stream 230 continuously or discontinuous In another embodiment of this invention, a portion of up to 100% of the carboxylic acid composition 110 may be directed directly to a secondary oxidation zone 335 without being subjected to the liquid displacement zone 225. In another embodiment of the invention, up to 100% of the feed to zone 235 of purge may be a stream 630 of mother liquor generated in a solid-liquid separation zone 625 that also produces the stream 610 of purified wet cake.

In yet another embodiment, up to 100% of the feed to the purge zone 235 may be mother liquors generated in a secondary liquid displacement zone located somewhere down the secondary oxidation zone 325. A secondary liquid displacement zone is not shown in Figure 1, and comprises equipment such as that described for the liquid displacement zone 225 located after the primary oxidation zone 125, and must be located after the oxidation zone 335 high school.

Step (c) comprises oxidizing the low impurity suspension stream 210 in a secondary oxidation zone 335 to form a purified suspension stream 310. In one embodiment of the invention, the low impurity suspension stream 210 is directed to a secondary oxidation zone 335 where it is heated between 115 degrees C. and 220 degrees C., and preferably between 120 degrees C. and 200 degrees C. and it is further oxidized with an oxidizing gas, such as air, fed by line 320 to produce a stream of purified suspension 310. The secondary oxidation zone comprises at least one oxidation reactor vessel. In one embodiment, the secondary oxidation zone may be one or more oxidation vessels. When the carboxylic acid in the low impurity suspension stream 210 is FDCA, the secondary oxidation zone is operated at a temperature ranging between 115 degrees C. and 220 degrees C., preferably between 120 degrees C. and 200 degrees C. , and stream 210 is further oxidized with an oxidizing gas stream fed by line 320 to produce a purified suspension stream 310.

Generally, the oxidation in the secondary oxidation zone 335 is at a higher temperature than the oxidation in the primary oxidation zone 125 to improve the removal of impurities. In one embodiment, the secondary oxidation zone 335 operates at 30 ° C, 20 ° C, and preferably 10 ° C higher than the oxidation temperature in the primary oxidation zone 125 to improve impurity removal. The secondary oxidation zone 335 can be heated directly with solvent vapor or water vapor through stream 320 or indirectly by any means known in the art.

Further purification of the low impurity suspension stream 210 is achieved in the secondary oxidation zone by a mechanism that involves the recrystallization or growth of crystals and the oxidation of impurities and intermediates, including the FFCA. One of the functions of the secondary oxidation zone is to convert FFCA to FDCA. FFCA is considered monofunctional in relation to a polyester condensation reaction because it contains only one carboxylic acid. FFCA is present in stream 110 of carboxylic acid composition and suspension stream 210 of low impurity. FFCA is generated in zone 125 of primary oxidation because the reaction of 5-HMF to FFCA can be approximately eight times faster than the reaction of FFCA to the desired di-functional product FDCA. Additional air or molecular oxygen can be fed in stream 320 to secondary oxidation zone 335 in an amount necessary to oxidize a substantial portion of partially oxidized products, such as FFCA in stream 210 to the corresponding FDCA carboxylic acid. In general, at least 70% by weight of the FFCA present in the low impurity suspension stream 210 is converted to FDCA in the secondary oxidation zone 335. Preferably, at least 80% by weight of the FFCA present in the low impurity suspension stream 210 is converted to FDCA in the secondary oxidation zone 335 and, most preferably, at least 90% by weight of the FFCA present in the Low impurity suspension stream 210 is converted to FDCA in zone 335 of secondary oxidation. Significant concentrations of monofunctional molecules such as FFCA in the dried purified FDCA product are particularly detrimental to polymerization processes, since they can act as chain terminators during the polyester condensation reaction.

The amount of oxygen fed into the secondary oxidation zone 335 is controlled to limit the burning of organic molecules to CO ² . The amount of oxygen in stream 330 is monitored and used to control the amount of oxygen fed into stream 320. Another function of the secondary oxidation zone 335 is to dissolve and recrystallize the solids present in the low impurity suspension stream 210 fed to the secondary oxidation zone. At least 10% by weight, 25% by weight, 50% by weight and, preferably, at least 85% by weight of solid impurities and oxidation by-products in stream 210 that is fed to oxidation zone 335 Secondary solution goes into solution as the FDCA particles dissolve and recrystallize in the secondary oxidation zone 335. The residual gas from the secondary oxidation zone is extracted through line 330 and fed into a recovery system where the solvent is removed from the residual gas comprising volatile organic compounds (VOCs). VOCs that include methyl bromide can be treated, for example, by incineration in a catalytic oxidation unit. The purified suspension stream 310 generated in the secondary oxidation zone is directed to the crystallization zone 425.

Step (d) comprises crystallizing the secondary oxidation suspension 310 in a crystallization zone 425 to form a crystallized suspension stream 410. In general, the crystallization zone 425 comprises at least one crystallizer. The vapor of the crystallization zone can be condensed in at least one condenser and returned to the crystallization zone 425 or directed outside the crystallization zone 425. Optionally, the condenser liquid or the vapor product of the crystallization zone can be recycled, or it can be extracted or sent to an energy recovery device. In addition, the residual crystallizing gas is removed through line 420 and can be directed to a recovery system where the solvent is removed, and the crystallizing gas comprising VOCs can be treated, for example, by incineration in a catalytic oxidation unit. When the carboxylic acid is FDCA, the purified suspension stream 310 of the secondary oxidation zone 335 is fed to a crystallization zone 425 comprising at least one crystallizer where it is cooled to a temperature between 40 degrees C. and 175 degrees C to forming a stream 410 of crystallized suspension, preferably at a temperature between 50 degrees C to 170 degrees C, and more preferably from 60 degrees C to 165 degrees C.

The crystallized suspension stream 410 is then directed to a cooling zone 430 to generate a crystallized cooled suspension stream 510. The cooling of the crystallized suspension stream 410 can be achieved by any means known in the art. Typically, the cooling zone 430 comprises an expansion tank. The temperature of stream 510 may vary from 35 ° C to 160 ° C, from 45 ° C to 120 ° C, and preferably from 55 ° C to 95 ° C.

In another embodiment, a portion of up to 100% of the secondary oxidation suspension stream 310 is directed directly to the cooling zone 425, therefore, the portion is not subject to a crystallization zone 430. In yet another embodiment, a portion of up to 100% of the crystallized suspension stream 410 is directed directly to a secondary liquid displacement zone that is not illustrated in Figure 1. Up to 100% of the effluent of the suspension comprising FDCA of a secondary liquid displacement zone can be directed to the solid-liquid separation zone 625 and directly directed to the cooling zone 430. The function of the secondary liquid displacement zone is to displace a portion of solvent in the suspension stream 410 crystallized with fresh solvent and or water where a portion must be greater than 5 percent by weight. The secondary liquid displacement zone is separated and is distinct from the liquid displacement zone 225 located after the primary oxidation zone 125. The same type of equipment can be used for the primary and secondary liquid displacement zones. In yet another embodiment, the crystallized suspension stream 410 can be directed directly to the solid-liquid separation zone 625 without first being processed in the cooling zone 430.

Step (e) comprises isolating, washing and dehydrating solids present in the chilled crystallized suspension stream 510, in the solid-liquid separation zone 625. These functions can be achieved in a single solid-liquid separation device or multiple solid-liquid separation devices. The solid liquid separation zone 625 comprises at least one solid-liquid separation device capable of separating solids and liquids, washing solids with a stream 620 of washing solvent and reducing the% moisture in the washed solids to less than 30% by weight , less than 25% by weight, less than 20% by weight, less than 15% by weight, and preferably less than 10% by weight.

The equipment suitable for the solid-liquid separation zone 625 can normally comprise, but is not limited to, the following types of devices: centrifuges, cyclones, rotary drum filter, band filters, pressure leaf filters, candle filters , etc. The preferred solid-liquid separation device for the solid-liquid separation zone 625 is a rotary pressure drum filter. The temperature of the cooled crystallized suspension water vapor 510 which is directed to the solid-liquid separation zone 625 may vary from 50 ° C to 140 ° C, from 70 ° C to 120 ° C, and is preferably 75 ° C at 95 ° C. The washing solvent stream 620 comprises a liquid suitable for displacing and washing the mother liquor of the solids.

In one embodiment of the invention, a suitable washing solvent comprises acetic acid and water. In another embodiment, a suitable solvent comprises water up to 100% water. The temperature of the washing solvent may vary from 20 ° C to 135 ° C, 40 ° C and 110 ° C, and preferably from 50 ° C to 90 ° C. The amount of washing solvent used is defined as the washing ratio and is equal to the washing mass divided by the mass of solids discontinuously or continuously. The wash ratio may vary from 0.3 to 5, from 0.4 to 4, and preferably from 0.5 to 3. After the solids are washed in the solid-liquid separation zone, they are dehydrated. Dehydration involves reducing the mass of moisture present with the solids to less than 30% by weight, less than 25% by weight, less than 20% by weight, less than 15% by weight and most preferably less than 10% by weight resulting in the generation of a stream of purified wet cake. In one embodiment, dehydration is performed on a filter by passing a stream 610 of gas through the solids to displace the free liquid after the solids have been washed with a washing solvent. In another embodiment, dehydration is achieved by centrifugal forces in a perforated cuvette or in a solid cuvette centrifuge. The stream 630 generated in the solid-liquid separation zone 625 is a mother liquor stream comprising oxidation solvent, catalyst and some impurities and oxidation by-products. In one embodiment, a portion of stream 630 is directed to a purge zone 235 and a portion is directed back to the zone of primary oxidation where a portion is at least 5% by weight. The dissolution stream 640 is also generated in the solid-liquid separation zone 625 and comprises a portion of mother liquors present in the stream 510 and washing solvent where the ratio of mother liquor mass to washing solvent mass is lower than 3 and preferably less than 2.

Step (f) comprises drying the purified wet cake stream 610 in a drying zone 725 to generate a dry purified carboxylic acid 710 and a steam stream 720. In one embodiment, the steam stream 720 comprises washing solvent steam. In another embodiment, steam stream 720 comprises oxidation solvent and wash solvent. The drying zone 725 comprises at least one dryer and can be achieved by any means known in the art that is capable of evaporating at least 10% of the volatiles left in the stream 610 of purified wet cake to produce the carboxylic acid 710 purified dry comprising FDCA purified and a steam stream 720. For example, indirect contact dryers include, but are not limited to, a rotary water vapor tube dryer, a single-axis Porcupine RTM dryer and a Bepex Solidaire RTM dryer. Direct contact dryers include, but are not limited to, a fluid bed dryer and drying on a transport line can be used to dry to produce stream 710. Purified dry carboxylic acid 710 comprising purified FDCA can be a carboxylic acid composition with less than 8% moisture, preferably less than 5% moisture, and more preferably less than 1% moisture, and even more preferably less than 0.5%, and even more preferably less than 0.1%. In another embodiment of this invention, if the liquid portion of the purified wet cake stream 610 comprises water and contains less than 0.1% by weight acetic acid, less than 500 ppm by weight acetic acid and, preferably, less than 200 ppm by weight, stream 610 can be fed directly to a polymerization zone without first drying.

In one embodiment of the invention, a vacuum system can be used to extract the steam stream 720 from the drying zone 725. If a vacuum system is used in this manner, the pressure of stream 720 at the dryer outlet may vary from 1.01 bar (760 mmHg) to 0.53 bar (400 mmHg), from 1.01 bar (760 mmHg) to 0.8 bar ( 600 mmHg), from 1.01 bar (760 mmHg) to 0.93 bar (700 mmHg), from 1.01 bar (760 mmHg) to 0.95 bar (720 mmHg), and from 1.01 bar (760 mmHg) to 0 , 98 bar (740 mmHg), where the pressure is measured in mmHg above the absolute vacuum. The content of the conduit between the solid-liquid separation zone 625 and the drying zone 725 used to transfer the purified wet cake stream 610 comprises a wet cake stream and gas where the gas is the continuous phase. The pressure at the exit of the solid-liquid separation zone 625 may be close to the pressure where the steam stream 720 leaves the drying zone 725, where close is defined as within 0.14 bar (2 psig), within 0.06 bar (0.8 psig), and preferably within 0.03 bar (0.4 psig).

In one embodiment of the invention, the dried purified carboxylic acid 710 has a b * less than 9.0. In another embodiment of the invention, the color b * of the dried purified carboxylic acid 710 is less than 6.0. In another embodiment of the invention, the color b * of the dried purified carboxylic acid 710 is less than 5.0. In another embodiment of the invention, the color b * of the dried purified carboxylic acid 710 is less than 4.0. In another embodiment of the invention, the color b * of the dried purified carboxylic acid 710 is less than 3. The color b * is one of the three color attributes measured in an instrument based on spectroscopic reflectance. A Hunter Ultrascan XE instrument in reflectance mode is usually the measuring device. Positive readings mean the degree of yellow (or absorbance of blue), while negative readings mean the degree of blue (or absorbance of yellow).

It should be appreciated that the process areas described above can be used in any other logical order to produce the dried purified carboxylic acid 710. It should also be appreciated that when the procedural zones are rearranged, the procedural conditions may change. It is also understood that all percentage values are percentages by weight.

Step (g) is an optional step that comprises decolorizing the FDCA in this process or an esterified FDCA with a diol stream by hydrogenation. In one embodiment, the diol stream comprises ethylene glycol. In another embodiment, the diol stream comprises cyclohexane diol isomers, preferably the 1-4 cyclohexane diol isomer. The discoloration of the FDCA in this procedure or an esterified FDCA can be achieved by any means known in the art and is not limited to hydrogenation. However, for example, in one embodiment of the invention, the discoloration can be achieved by reacting a carboxylic acid that has undergone an esterification treatment, for example with ethylene glycol, with molecular hydrogen in the presence of a hydrogenation catalyst in a reactor zone to produce a solution of discolored carboxylic acid or a discolored ester product.

For the reactor zone, there are no special limitations in the form or construction thereof, subject to an arrangement that allows the supply of hydrogen to effect intimate contact of the carboxylic acid or the ester product with the catalyst in the reactor zone. Typically, the hydrogenation catalyst is generally a single Group VIII metal or a combination of Group VIII metals. Preferably, the catalyst is selected from a group consisting of palladium, ruthenium, rhodium and a combination thereof. The reactor zone comprises a hydrogenation reactor that operates at a temperature and pressure sufficient to hydrogenate a portion of the characteristically yellow compounds to colorless derivatives.

Examples:

This invention can be further illustrated by the following examples of embodiments thereof, although it will be understood that these examples are included for illustrative purposes only and are not intended to limit the scope of the invention unless specifically indicated otherwise.

Set of Examples 1

In examples 1a-3d, glacial acetic acid and catalyst components in concentrations described in Tables 1, 2 and 3 were transferred to a 300 mL titanium autoclave equipped with a high pressure condenser, a baffle and an Isco pump . Cobalt, manganese and ionic bromine were provided as cobalt (II) acetate tetrahydrate, manganese (II) acetate and sodium bromide and / or aqueous hydrobromic acid, respectively. The autoclave was pressurized with approximately 3.4 bar (50 psig) of nitrogen and the homogeneous mixture was heated to desired temperature in a closed system (i.e. no gas flow) with stirring. At the reaction temperature, an air flow of 1500 sccm was introduced at the bottom of the solution and the reaction pressure was adjusted to the desired pressure. A solution of 5-HMF / 5-AMF / 5-EMF in acetic acid was fed to the mixture at a rate of 0.833 mL / min through a high pressure Isco pump (this is t = 0 for the reaction time ). After 30 seconds from the start of the substrate feed, 1.0 g of peracetic acid in 5.0 mL of acetic acid was introduced using a booster to start the reaction. The feed was stopped after 1 h and the reaction continued for an additional hour under the same conditions of air flow, temperature and pressure. Once the reaction time was completed, the air flow was stopped and the autoclave was cooled to room temperature and depressurized. The heterogeneous mixture was filtered to isolate the crude FDCA. The mass of the filtrate was recorded. The crude f Dc A was washed with 60 mL of acetic acid twice and then twice with 100 mL of DI water. The washed crude FDCA was dried in the oven at 110 ° C under vacuum overnight and then weighed. The solid and the filtrate were analyzed by gas chromatography using the BSTFA derivatization method. The residual gas was analyzed for CO and CO ² by ND-1R (ABB, Advanced Optima) and O ² by a paramagnetism detection system (Servomex, model 1440).

Analytics

Gas chromatography method. The procedure samples were analyzed using a Shimadzu Model 2010 gas chromatograph (or equivalent) equipped with a separator / heater injector (300 ° C) and a flame ionization detector (300 ° C). A capillary column (60 meters x 0.32 mm internal diameter) coated with (6% cyanopropylphenyl) methylpolysiloxane at 1.0 pm film thickness (as DB-1301 or equivalent) was used. Helium was used as a carrier gas with an initial column head pressure of 2.06 bar (29.5 psi) and an initial column flow of 3.93 mL / minute while the linear velocity of the carrier gas of 45 cm / second remained constant throughout the oven temperature program. The column temperature was programmed as follows: the initial oven temperature was set at 80 ° C and maintained for 6 minutes, the oven was increased to 150 ° C at 4 ° C / minute and maintained at 150 ° C for 0 minutes, the oven was increased to 240 ° C at 10 ° C / minute and kept at 240 ° C for 5 minutes, then the oven was increased to 290 ° C at 10 ° C / minute and kept at 290 ° C for 17.5 minutes (the total execution time was 60 minutes). 1.0 pL of the sample solution prepared with a separation ratio of 40: 1 was injected. The EZ-Chrom Elite chromatography data system software was used for data acquisition and processing. The sample was prepared by weighing 0.1 g (with an accuracy of 0.1 mg) of the sample in a GC vial and adding 200.0 pL of ISTD solution (1% by volume of pyridine decane) and 1000 pL of BSTFA (N , O-bis (trimethylsilyl)) trifluoroacetamide) with 1% TMSCI (trimethylchlorosilane) in the GC vial. The content was heated at 80 ° C for 30 minutes to ensure complete derivatization. 1.0 pL of this sample solution prepared for GC analysis was injected.

Color measurement. 1) Assemble the Carver press die as indicated in the instructions: place the die in the base and place the 40 mm lower cylinder with the polished side up.

2) Place a 40 mm plastic cup (Chemplex Plasticup, 39.7 x 6.4 mm) on the die.

3) Fill the glass with the sample to be analyzed. The exact amount of sample added is not important.

4) Place the upper part of the 40 mm cylinder with the polished side down on the sample.

5) Insert the plunger into the die. No "inclination" should be displayed on the assembled die.

6) Place the die in the Carver press, making sure it is close to the center of the bottom plate. Close the security door.

7) Lift the die until the top plate makes contact with the plunger. Apply> 9072 kg (20000 lbs) of pressure. Then, allow the die to remain under pressure for approximately 3 minutes (the exact time is not critical).

8) Relieve the pressure and lower the bottom plate that holds the die.

9) Remove the die and remove the glass. Place the glass in a labeled plastic package (Nasco Whirl-Pak 4 oz).

10) Use a HunterLab Colorquest XE colorimeter, create the following method (Hunterlab EasyQuest QC software, version 3.6.2 or later).

Mode: RSIN-LAV (Reflectance Specular Included-Large Area View) Measurements:

CIE L * a * b *

CIE X Y Z

11) Standardize the instrument as indicated by the software using the light trap accessory and the certified white ceramic accessory pressed against the reflectance port.

12) Execute a green ceramic standard using certified white ceramics and compare the CIE X, Y and Z values obtained with the certified ceramics values. The values obtained must be ± 0.15 units in each scale of the established values.

13) Analyze the sample in the package by pressing it against the reflectance port and obtaining the spectrum and the L *, a *, b * values. Obtain duplicate readings and average the values for the report.

Interpretation of results:

During the oxidation of 5-HMF to FDCA, the position of the alcohol (ArCH ² OH) was converted to carboxylic acid (ArCOOH) mainly through aldehyde (ArCHO), eq 3. Examples 1a and 1b (Table 1) using Catalytic systems consisting of cobalt, manganese and a source of aqueous hydrobromic acid yield a yield of approximately 90% FDCA with a purity> 98% solid of crude FDCA and with a b * of approximately 6. The solid FDCA solid also Contains 5-formylfuran-2-carboxylic acid (FFCA), only hydroxylmethyl groups are oxidized to carboxylic acid groups, due to incomplete oxidation.

The oxidation of 5-AMF (which does not belong to the invention), which contains an oxidizable ether and aldehyde residues, produced FDCA, FFCA and acetic acid, eq 4. Examples 2a to 2b (Table 2) demonstrate that it can be achieved. a minimum of 99% pure FDCA purity with a b * of approximately 7 or less using a catalytic system of cobalt, manganese and aqueous hydrobromic acid.

The oxidation of 5-EMF (which does not belong to the invention), which contains an oxidizable ether and aldehyde residues, produced FDCA, FFCA, 5- (ethoxycarbonyl) furan-2-carboxylic acid (EFCA) and acetic acid, eq 5. Examples 3a to 3d (Table 3) show that a minimum of 96% solid FDCA can be achieved with a b * of about 6 or less using a catalytic system of cobalt, manganese and aqueous hydrobromic acid.

It is very important to keep in mind that in a continuous procedure under the same conditions described in the report of this invention (which was performed as a discontinuous procedure) an even greater purity of crude FDCA is expected due to efficient mixing, relatively concentrations low reactive intermediates and other reasons familiar to those skilled in the art.

Table 1. Result of semi-continuous reactions performed as described above.

using power * 5-HMF

* P = 9 bar (130 psig).

Table 1. Result of the reaction is semi-continuous, as described below.

using power * 5-AMF

* P = 9 bar (130 psig).

Table 3. Result of semi-continuous reactions performed as described above.

using power * EMF

* P = 9 bar (130 psig)

Set of Examples 2

5-HMF air oxidation was carried out using cobalt, manganese and an ionic bromine catalyst system in an acetic acid solvent. After the reaction, the heterogeneous mixture was filtered to isolate the crude FDCA. The crude FDCA was washed with acetic acid twice and then twice with DI water. The washed crude FDCA was dried in an oven at 110 ° C under vacuum overnight. The solid and the filtrate were analyzed by gas chromatography using the BSTFA derivatization method. b * of the solid was measured using a Hunter Ultrascan XE instrument. As shown in Table 4, conditions for generating FDCA yields of up to 89.4%, b * <6, and low carbon burning (<0.0006 mol / min CO CO ² ) have been discovered (Examples 4a and 4b are for comparison ).

Set of Examples 3

In examples 5a-5h, glacial acetic acid and catalyst components at the concentrations described in Table-5 were transferred to a 300 mL titanium autoclave equipped with a high pressure condenser, a baffle and an Isco pump. Cobalt, manganese and ionic bromine were provided as cobalt (II) acetate tetrahydrate, manganese (II) acetate and sodium bromide and / or aqueous hydrobromic acid, respectively. The autoclave was pressurized with approximately 3.4 bar (50 psig) of nitrogen and then the homogeneous mixture was heated to the desired temperature in a closed system (i.e., without gas flow) with stirring. At the reaction temperature, an air flow of 1500 sccm was introduced at the bottom of the solution and the reaction pressure was adjusted to the desired pressure. A solution of 5-HMF in acetic acid was fed to the mixture at a rate of 0.833 mL / min through a high pressure Isco pump (this is t = 0 for the reaction time). After 30 seconds from the start of the 5-HMf feed, 1.0 g of peracetic acid in 5.0 mL of acetic acid was introduced using a booster to start the reaction. The feed was stopped after 1 h and the reaction continued for another 1 hour under the same conditions of air flow, temperature and pressure. Once the reaction time was completed, the air flow was stopped and the autoclave was cooled to room temperature and depressurized. The heterogeneous mixture was filtered to isolate the crude FDCA. The mass of the filtrate was recorded. The crude FDCA was washed with 60 mL of acetic acid twice and then twice with 100 mL of DI water. The washed crude FDCA was oven dried at 110 ° C under vacuum overnight and then weighed. The solid and the filtrate were analyzed by gas chromatography using the BSTFA derivatization method.

The residual gas was analyzed for CO and CO ² by ND-1R (ABB, Advanced Optima) and O ² by a paramagnetism detection system (Servomex, model 1440).

Analytics

Gas chromatography method. The procedure samples were analyzed using a Shimadzu Model 2010 gas chromatograph (or equivalent) equipped with a separator / heater injector (300 ° C) and a flame ionization detector (300 ° C). A capillary column (60 meters x 0.32 mm internal diameter) coated with (6% cyanopropylphenyl) methylpolysiloxane at 1.0 pm film thickness (as DB-1301 or equivalent) was used. Helium was used as a carrier gas with an initial column head pressure of 2.06 bar (29.5 psi) and an initial column flow of 3.93 mL / minute while the linear velocity of the carrier gas of 45 cm / second remained constant throughout the oven temperature program. The column temperature was programmed as follows: the initial oven temperature was set at 80 ° C and maintained for 6 minutes, the oven was increased to 150 ° C at 4 ° C / minute and maintained at 150 ° C for 0 minutes, the oven was increased to 240 ° C at 10 ° C / minute and kept at 240 ° C for 5 minutes, then the oven was increased to 290 ° C at 10 ° C / minute and held at 290 ° C for 17.5 minutes (the total execution time was 60 minutes). 1.0 pL of the sample solution prepared with a separation ratio of 40: 1 was injected. The EZ-Chrom Elite chromatography data system software was used for data acquisition and processing. The sample was prepared by weighing 0.1 g (with an accuracy of 0.1 mg) of the sample in a GC vial and adding 200.0 pl of ISTD solution (1% by volume of dean in pyridine) and 1000 pL of BSTFA (N , O-bis (trimethylsilyl)) trifluoroacetamide) with 1% TMSCI (trimethylchlorosilane) in the GC vial. The content was heated at 80 ° C for 30 minutes to ensure complete derivatization. 1.0 pL of this sample solution prepared for GC analysis was injected.

PH measurement. The electrode for determining the non-aqueous pH and the millivolts was a Schott N6480-eth series electrode. The LiCI / EtOH filler solution was replaced with (Et) ⁴ N + Br / et.lengl.col. The electrode response was monitored by Multi-T 2.2 software through a Sensolab interface box of the cdv-70 series from Jensen Systems. Buffers (pH 4 and 7) were purchased from VWR, and the filling solution of (Et) ⁴ N + Br / ethylene glycol was from Metrohm.

To perform the pH measurements, a non-aqueous electrode was initially calibrated using aqueous buffers of 4 and 7, which allowed the electrode to equilibrate with each one for two or three minutes before calibrating at the respective level. Once the electrode was calibrated within 97.5% of the 59.2 millivolt slope, the samples were divided into portions (~ 15 mL) in smaller vials with mini-Teflon stirring bars. The samples were then placed on a stir plate and the electrode was introduced into the sample. The depth of the electrode was adjusted to where the sample covered approximately half of the slide junction. Once the sample and electrode were ready, the sample was measured for non-aqueous pH for a period of three minutes. The time was sufficient for the balance between the electrode and the sample. Between each sample measurement, the electrode was rinsed with Millipore grade water and cleaned with a Kimwipe. The results were recorded in non-aqueous pH units. The millivolt results were also recorded.

Color measurement. 1) Assemble the Carver press die as indicated in the instructions: place the die in the base and place the 40 mm lower cylinder with the polished side up.

2) Place a 40 mm plastic cup (Chemplex Plasticup, 39.7 x 6.4 mm) on the die.

3) Fill the glass with the sample to be analyzed. The exact amount of sample added is not important.

4) Place the upper part of the 40 mm cylinder with the polished side down on the sample.

5) Insert the plunger into the die. No "inclination" should be displayed on the assembled die.

6) Place the die in the Carver press, making sure it is close to the center of the bottom plate. Close the security door.

7) Lift the die until the top plate makes contact with the plunger. Apply> 9072 kg (20000 lbs) of pressure. Then, allow the die to remain under pressure for approximately 3 minutes (the exact time is not critical).

8) Relieve the pressure and lower the bottom plate that holds the die.

9) Remove the die and remove the glass. Place the glass in a labeled plastic package (Nasco Whirl-Pak 4 oz).

10) Use a HunterLab Colorquest XE colorimeter, create the following method (Hunterlab EasyQuest QC software, version 3.6.2 or later)

Mode: RSIN-LAV (Reflectance Specular Included-Large Area View) Measurements:

CIE L * a * b *

CIEXYZ

11) Standardize the instrument as indicated by the software using the light trap accessory and the certified white ceramic accessory pressed against the reflectance port.

12) Execute a green ceramic standard using certified white ceramics and compare the CIE X, Y and Z values obtained with the certified ceramics values. The values obtained must be ± 0.15 units in each scale of the established values.

13) Analyze the sample in the package by pressing it against the reflectance port and obtaining the spectrum and the L *, a *, b * values. Obtain duplicate readings and average the values for the report.

Interpretation of results:

Examples 5c, 5d, 5e and 5f (Table-5) using catalytic systems consisting of cobalt, manganese and aqueous hydrobromic acid or aqueous hydrobromic acid and sodium bromide as a source of bromide that produces an FDCA yield of approximately 90 %, minimum colored impurities (measured by b *) and a minimum level of CO and CO ² (COx, mol / min) in the waste gas. One of the reasons for the differences in activity between hydrobromide and sodium bromide, in a single discontinuous reaction, is due to a faster oxidation of HBr by Mn (III), eq 6, than sodium bromide (it is about 22 times faster: Jiao, XJ; Espenson, JH Inorg. Chem. 2000, 39, 1549). The activity of the hydrobromic acid or sodium bromide reaction media can be increased by the addition of a strong Bronsted acid (such as triflic acid, HCI, etc.).

Mn (OAc) at 2HBr ^ 2HOAc Mn (OAc) Br ² ^ Mn (OAc) ² + HB ^ - (6)

Comparative examples 5g and 5h show the inhibitory effect of excess manganese. Therefore, it is desirable to limit the amount of manganese, during the oxidation process, to achieve high FDCA performance. Examples 5a and 5b are also for comparison.

It is very important to keep in mind that in a continuous process under the same conditions described in the report of this invention (performed as a discontinuous procedure) a yield greater than 90% of FDCA was expected due to the efficient supply of oxygen and mixing.

Example set 4

In Examples 1-34, 72, 73, 85, 86, 91, 92 and 93, glacial acetic acid and catalyst components in the concentrations described in Tables 6 and 7 were transferred to a 300 mL titanium autoclave equipped with a high pressure condenser, a baffle and an Isco pump. Cobalt, manganese and ionic bromine were provided as cobalt (II) acetate tetrahydrate, manganese (II) acetate and sodium bromide / aqueous hydrobromic acid, respectively. The autoclave was pressurized with approximately 3.4 bar (50 psig) of nitrogen and then the homogeneous mixture was heated to the desired temperature in a closed system (i.e., without gas flow) with stirring. At the reaction temperature, an air flow of 1500 sccm was introduced at the bottom of the solution and the reaction pressure was adjusted to the desired pressure. A solution of 5-HMF in acetic acid was fed to the mixture at a rate of 0.833 mL / min through a high pressure Isco pump (this is t = 0 for the reaction time). After 30 seconds from the start of the 5-HMF feed, 1.0 g of peracetic acid in 5.0 mL of acetic acid was introduced using a pressure lifter to start the reaction. The feed was stopped after 1 h and the reaction continued for another 1 hour under the same conditions of air flow, temperature and pressure. Once the reaction time was completed, the air flow was stopped and the autoclave was cooled to room temperature and depressurized. The heterogeneous mixture was filtered to isolate the crude FDCA. The mass of the filtrate was recorded. The crude f Dc A was washed with 60 mL of acetic acid twice and then twice with 100 mL of DI water. The washed crude FDCA was dried in the oven at 110 ° C under vacuum overnight and then weighed. The solid and the filtrate were analyzed by gas chromatography using the BSTFA derivatization method. A typical GC chromatogram is shown for crude FDCA sample isolated in Figure 2. The purity of this solid was confirmed by NMR spectroscopy, Figures 3 and 4.

The residual gas was analyzed for CO and CO ² by ND-1R (ABB, Advanced Optima) and O ² by a paramagnetism detection system (Servomex, model 1440).

Analytics

Gas chromatography method. The process sample was analyzed using a Shimadzu Model 2010 gas chromatograph (or equivalent) equipped with a separator / heater injector (300 ° C) and a flame ionization detector (300 ° C). A capillary column (60 meters x 0.32 mm internal diameter) coated with (6% cyanopropylphenyl) methylpolysiloxane at 1.0 pm film thickness (as DB-1301 or equivalent) was used. Helium was used as a carrier gas with an initial column head pressure of 2.06 bar (29.5 psi) and an initial column flow of 3.93 mL / minute, while the linear velocity of the carrier gas of 45 cm / second remained constant for The entire oven temperature program. The column temperature was programmed as follows: the initial oven temperature was set at 80 ° C and maintained for 6 minutes, the oven was increased to 150 ° C at 4 ° C / minute and maintained at 150 ° C for 0 minutes, the oven was increased to 240 ° C at 10 ° C / minute and kept at 240 ° C for 5 minutes, then the oven was increased to 290 ° C at 10 ° C / minute and held at 290 ° C for 17.5 minutes (the total execution time was 60 minutes). 1.0 pL of the sample solution prepared with a separation ratio of 40: 1 was injected. The EZ-Chrom Elite chromatography data system software was used for data acquisition and processing. Sample preparation was performed by weighing 0.1 g (with an accuracy of 0.1 mg) of the sample in a GC vial and adding 200.0 pL of ISTD solution (1% by volume of pyridine dean) and 1000 pL of BSTFA (N , O-bis (trimethylsilyl) trifluoroacetamide) with 1% TMSCI (trimethylchlorosilane) in the GC vial. The content was heated at 80 ° C for 30 minutes to ensure complete derivatization. 1.0 pL of this sample solution prepared for GC analysis was injected.

Interpretation of results:

Experiments 1-34, Table 6, were performed by varying the temperature, pressure and concentration levels of cobalt and bromine to determine the optimal conditions and catalytic compositions that produce a very high yield of FDCA with a minimum amount of burning of carbon. In this invention, the weight ratio of cobalt to manganese was deliberately kept very high (i.e., 21) in all reactions to avoid the inhibitory effect of excess manganese, especially below 160 ° C.

As can be seen in Figure 5 under the reaction conditions investigated in this invention, the factor that has the greatest impact on FDCA performance is temperature. It is also important to keep in mind that yield increases with increasing concentrations of cobalt and bromine.

The data presented in Table 6 were used to develop a theoretical polynomial model to predict the performance of FDCA under different conditions, eq-7. Examples of predicted FDCA yields using this model are given in Table 7. Experiments No. 72, 73, 85 and 86, Table 7, were performed under the conditions provided. As can be seen in the results, they agree with the predicted values within the experimental error.

% yield of FDCA = -91.469 2.83 * T - 0.01 * P - 0.02 * [Co] 0.003 * [Br]

- 0.01 * T2 3.9 * 10'6 * [Co] 2 ........ (7)

Examples 91-93, Table 8, were performed under the conditions of United States patent applications (US2003 / 0055271 A1) using our configuration. As can be seen in Tables 6, 7 and 8, the conditions of the patent application gave a much lower FDCA yield than that of the present invention.

Table 7. Predicted returns of FDCA. 72, 73, 74.85 and 86 are experimental * results

'* Reason in weight charged to manganese = 21 for all exp e rim in cough

Example set 5 (comparative)

In examples 9a-11b, glacial acetic acid and catalyst components in concentrations described in Tables 9, 10 and 11 were transferred to a 300 mL titanium autoclave equipped with a high pressure condenser, a baffle and an Isco pump . Cobalt, manganese and ionic bromine were provided as cobalt (II) acetate tetrahydrate, manganese (II) acetate and aqueous hydrobromic acid, respectively. The autoclave was pressurized with approximately 3.4 bar (50 psig) of nitrogen and the homogeneous mixture was heated to the desired temperature in a closed system (i.e., without gas flow) with stirring. At the reaction temperature, an air flow of 1500 sccm was introduced at the bottom of the solution and the reaction pressure was adjusted to the desired pressure. A solution of 5-MF / 5-AMF / 5-EMF in acetic acid was fed to the mixture at a rate of 0.833 mL / min by means of a high pressure Isco pump (this is t = 0 for the reaction time). After 30 seconds from the start of the substrate feed, 1.0 g of peracetic acid in 5.0 mL of acetic acid was introduced using a pressure lifter to start the reaction. The feed was stopped after 1 h and the reaction continued for an additional hour under the same conditions of air flow, temperature and pressure. Once the reaction time was completed, the air flow was stopped and the autoclave was cooled to room temperature and depressurized. The heterogeneous mixture was filtered to isolate the crude FDCA. The mass of the filtrate was recorded. The crude FDCA was washed with 60 mL of acetic acid twice and then twice with 100 mL of DI water. The washed crude FDCA was oven dried at 110 ° C under vacuum overnight and then weighed. The solid and the filtrate were analyzed by gas chromatography using the BSTFA derivatization method.

The residual gas was analyzed for CO and CO ² by ND-1R (ABB, Advanced Optima) and O ² by a paramagnetism detection system (Servomex, model 1440).

Analytics

Gas chromatography method. The procedure samples were analyzed using a Shimadzu Model 2010 gas chromatograph (or equivalent) equipped with a separator / heater injector (300 ° C) and a flame ionization detector (300 ° C). A capillary column (60 meters x 0.32 mm internal diameter) coated with (6% cyanopropylphenyl) methylpolysiloxane at 1.0 pm film thickness (as DB-1301 or equivalent) was used. Helium was used as a carrier gas with an initial column head pressure of 29.5 psi and an initial column flow of 3.93 mL / minute, while the linear velocity of the carrier gas of 45 cm / second remained constant throughout the entire program. oven temperature The column temperature was programmed as follows: the initial oven temperature was set at 80 ° C and maintained for 6 minutes, the oven was increased to 150 ° C at 4 ° C / minute and maintained at 150 ° C for 0 minutes, the oven was increased to 240 ° C at 10 ° C / minute and kept at 240 ° C for 5 minutes, then the oven was increased to 290 ° C at 10 ° C / minute and held at 290 ° C for 17.5 minutes (the total execution time was 60 minutes). 1.0 pL of the sample solution prepared with a separation ratio of 40: 1 was injected. The EZ-Chrom Elite chromatography data system software was used for data acquisition and processing. The sample was prepared by weighing 01 g (with an accuracy of 0.1 mg) of the sample in a GC vial and adding 200.0 pL of ISTD solution (1% by volume of pyridine dean) and 1000 pL of BSTFA (N , O-bis (trimethylsilyl) trifluoroacetamide) with 1% TMSCI (trimethylchlorosilane) in the GC vial. The content was heated at 80 ° C for 30 minutes to ensure complete derivatization. 1.0 pL of this sample solution prepared for GC analysis was injected.

Interpretation of results:

5-AMF feeding studies

The oxidation of 5-AMF, which contains an oxidizable ester and aldehyde residues, produced FDCA, FFCA and acetic acid, eq 8. Experiments 9a-9k, Table 9, were performed by varying the temperature and concentration levels of cobalt and bromine to determine the optimal conditions and catalytic compositions that produce a very high yield of FDCA with a minimum amount of carbon burned. In this invention, the weight ratio of cobalt to manganese was deliberately kept very high (i.e., 21) in all reactions to avoid the inhibitory effect of excess manganese, especially below 160 ° C. An additional discussion on the mechanism of initiation and inhibition by Mn (II) in oxidation can be found in Zakharov, I. V. Kinetics and Catalysis 1998, 39, 485; and Jiao, X. J .; Espenson, J. H. Inorg. Chem. 2000, 39, 1549.

Table 9. Results of semi-continuous reactions performed as described above using 5-AMF * feed

As can be seen in Figure 6, under the reaction conditions investigated, in this invention, the factor that has the greatest impact on FDCA performance is temperature. It is also important to keep in mind that yield may increase with increasing concentrations of cobalt and bromine.

It is important to keep in mind that the same yield and selectivity can be obtained with the mixed raw materials of 5-HMF and 5-AMF with varying ratios of the two components.

5-EMF Feeding Study:

Oxidation of 5-EMF, which contains an oxidizable ether and aldehyde residues, produced FDCA, FFCA, 5- (ethoxycarbonyl) furan-2-carboxylic acid (EFCA) and acetic acid, eq 9.

Experiments 10a-10k, Table 10, were performed by varying the temperature and levels of cobalt and bromine to determine the optimal conditions and catalytic compositions that produce a very high yield of FDCA with a minimum amount of carbon burning. Similar to the 5-AMF oxidation described above, the weight ratio of cobalt to manganese was deliberately kept very high (i.e., 21) in all reactions to avoid the inhibitory effect of excess manganese, especially below 160 ° C

Table 10. Results of semi-continuous reactions performed as described above using 5-EMF feed *

As can be seen in Figure 7 under the reaction conditions investigated in this invention, the factor that has the greatest impact on FDCA performance is temperature. It is important to keep in mind that the same yield and selectivity can be obtained with the mixed 5-HMF and 5-EMF raw materials with varying ratios of the two components.

5-MF feeding study:

The oxidation of 5-MF, which contains a methyl and aldehyde residue, produced FDCA and FFCA eq 10. Experiments 11a and 11b Table 11, demonstrated that a moderate yield of FDCA can be obtained with high purity using 5-MF as the material of feeding.

Table 11. Results of semi-continuous reactions performed as described above with 5-MF * feed

It is very important to keep in mind that in a continuous procedure under the same conditions described in the report of this invention (which was performed as a discontinuous procedure) with different feedstocks, even higher yields of crude FDCA are expected due to a mixture efficient, relatively low concentrations of reactive intermediates and other reasons familiar to those skilled in the art.

Claims (15)

1. A process for producing a composition (710) of dry purified carboxylic acid comprising furan-2,5-dicarboxylic acid (FDCA), said process comprising step (a): step (a) comprises oxidizing in a primary oxidation zone (125) at least one oxidizable compound in a stream (30) of oxidizable raw material comprising 5-HMF in the presence of a stream (10) of oxidizing gas, a stream (20) of solvent comprising a saturated organic acid solvent having from 2 to 6 carbon atoms with the presence of water and a catalytic system at a temperature of 100 ° C to 220 ° C to produce a composition (110) of crude carboxylic acid comprising FDCA; wherein said primary oxidation zone (125) comprises at least one oxidation reactor and wherein said catalytic system comprises cobalt in a range of 500 ppm by weight to 6000 ppm by weight with respect to the weight of the liquid in the reaction medium, manganese in an amount ranging from 2 ppm by weight to 600 ppm by weight with respect to the weight of the liquid in the reaction medium and bromine in an amount ranging from 300 ppm by weight to 4500 ppm by weight with respect to the weight of the liquid in the reaction medium, where the ratio of cobalt to manganese by weight is at least 10: 1. 2. A method according to claim 1, comprising step (b): step (b) comprises directing the composition (110) of crude carboxylic acid and a stream (220) of fresh solvent to a liquid displacement zone (225) to produce a stream (230) of displaced mother liquor and a Low impurity suspension stream (210) comprising FDCA. 3. A method according to claim 2, comprising step (c): step (c) comprises oxidizing the low impurity suspension stream (210) in a secondary oxidation zone (335) to form a purified suspension stream (310). 4. A method according to claim 3, comprising step (d): step (d) comprises crystallizing the secondary oxidation suspension (310) in a crystallization zone (425) to form a crystallized suspension stream (410); and further comprises directing the crystallized suspension stream (410) to a cooling zone (430) to generate a cooled crystallized suspension stream (510). 5. A method according to claim 4, comprising step (e): step (e) comprises isolating, washing and dehydrating the solids present in the crystallized and cooled suspension stream (510) in a solid-liquid separation zone (625), where dehydrating implies reducing the mass of moisture present with the solids at less than 30% by weight which results in the generation of a stream (610) of purified wet cake. 6. A method according to claim 5, comprising step (f): step (f) comprises drying the stream of purified wet cake (610) in a drying zone (725) to generate the dried purified carboxylic acid (710) and a stream (720) of steam. 7. A process according to claim 1, wherein in step (a) said oxidation reactor comprises a bubble column. 8. A process according to claim 7, wherein in step (a) said catalyst system comprises cobalt in a range of 700 ppm to 4500 ppm by weight with respect to the weight of the liquid in the reaction medium, manganese in a amount ranging from 20 ppm by weight to 400 ppm by weight with respect to the weight of the liquid in the reaction medium and bromine in an amount ranging from 700 ppm by weight to 4000 ppm by weight with respect to the weight of the liquid in the medium of reaction. 9. A method according to claim 1, wherein in step (a) said catalyst system comprises cobalt in a range of 1000 ppm to 4000 ppm with respect to the weight of the liquid in the reaction medium, manganese in an amount that It ranges from 20 ppm to 200 ppm by weight with respect to the weight of the liquid in the reaction medium and bromine in an amount ranging from 1000 ppm to 4000 ppm by weight with respect to the weight of the liquid in the reaction medium. 10. A process according to claim 1, wherein in step (a) said carboxylic acid composition (110) comprises at least one carboxylic acid selected from the group consisting of FDCA and FFCA. 11. A process according to claim 1, wherein in step (a) said oxidation is carried out at a temperature ranging between 105 ° C and 180 ° C. 12. A process according to claim 7, wherein in step (a) said oxidation is carried out at a temperature ranging from 110 ° C to 160 ° C. 13. A process according to claim 1, wherein in step (a) said 5-HMF is greater than 2% by weight in said stream (30) of oxidizable raw material; or wherein in step (a) said 5-HMF is greater than 20% by weight in said stream (30) of oxidizable raw material; or wherein in step (a) said 5-HMF is greater than 50% by weight in said stream (30) of oxidizable raw material; or wherein in step (a) said 5-HMF is greater than 70% by weight in said stream (30) of oxidizable raw material. 14. A process according to claim 1, wherein in step (a) said process is for producing crude furan-2,5-dicarboxylic acid (FDCA), wherein said oxidizable compound is 5-HMF which is oxidized in the solvent comprising acetic acid with or without the presence of water with oxygen in the presence of said catalytic system, wherein the weight ratio of cobalt to manganese in the reaction mixture is 10 to 400 and the weight ratio of cobalt to bromine is 0.7 to 3.5, where the catalyst cobalt concentration can vary from 1000 ppm by weight to 6000 ppm, and the amount of manganese from 2 ppm by weight to 600 ppm by weight, and the amount of bromine from 300 ppm by weight at 4500 ppm by weight with respect to the total weight of the liquid in the reaction medium of the primary oxidation zone (125); and where the primary oxidizing reactor is characterized by a lower section where gas bubbles disperse in a continuous liquid phase. 15. A process according to claim 1, wherein in step (a) said process is for producing crude furan-2,5-dicarboxylic acid (FDCA), wherein said oxidizable compound is 5-HMF which is oxidized in a stream (30) of oxidizable raw material in the presence of a stream (10) of oxidizing gas, a stream (20) of solvent and at least one catalytic system in said primary oxidation zone (125); wherein said solvent stream (20) comprises acetic acid with or without the presence of water; wherein the weight ratio of cobalt to manganese in the reaction mixture is 10 to 400, and the weight ratio of cobalt to bromine is 0.7 to 3.5; and where the yield of FDCA is at least 90%.